I am trying to restore a a small black vintage pen. It has "Varsity" on the clip. It has a small hidden metal button at the end of the barrel that spins but does not come out. The section has a clear ink window and doesn't seem to be removable. Anyone have a notion of how I can dismantle this? Sorry, I don't own a digital camera. The nib reads "Writefine" if that is helpful. Thanks for any advice/info.

Sounds like a fairly standard button filler. The section should come out ("should" does not mean "will", of course), and the button, if like the Parker and Wearever versions, will tug out. There's a little lip at the bottom of it to keep it from just dropping out, but it should yield under the fingers of a person of average strength. The section MIGHT be threaded, so try twisting, and some gentle dry heat should be applied at any rate to loosen up both the plastic and any adhesives (hopefully just shellac) that are keeping it in place.

The caveat to the above is that I've never had a pen of that particular make in hand, so I'm speaking in generalities. I'd wait a day or two before acting on my advice, as someone might say, "DON'T LISTEN TO THE CRAZY MAN!"